(Android 2.2) Best body/housing and general haptics. Also quite fast (to me it seems faster than the Galaxy). Also I prefer the mechanical 4 buttons over the soft buttons of the Galaxy.
OK-ish PC-Software (HTC Sync)installable from the phone, but this does not really matter, because it updates over the air (!).

My favourite: The HTC Desire .. can't see why, but it seems to beat the Galaxy S.

Also the Xperia X10 did only last one and a half battery cycles. Simply does not charge ever since. Seems to be a bad contact in the USB/charging plug. I hope to be able to register this as a DoA. I'll be posting the results here.

The activation experience was the same and excellent for all of them [1] - as long as you are not paranoid of Google. Just exporting the contacts with the good old Nokia PC Suite from their old Nokia phones, import the .csv file into their Google contacts, and have the phone sync. Done.Gmail is there, market place is there. No fussing around with iTunes etc etc...

I guess I should try the HTC Desire Z because of the physical QUERTY keyboard. But I have to test this first; I do have my doubts about Android with a physical keyboard... does not seem to fit (from my brief X10 mini pro experience). See how this measures against the near-perfect keyboard on the E71 (probably the best feature of the E71... along with the phone stability and battery lifetime).

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[1] Well I can only guess for the Galaxy, because my wife activated and personalized it herself while she was on vacation during summer. I guess this is quite a good benchmark.